1. Heat olive oil in a large skillet over medium heat. Add the chopped onion and minced garlic. Sauté until softened and fragrant, about 3 to 4 minutes.

2. Add ground beef to the skillet. Break it apart and cook until fully browned, about 6 to 8 minutes. Season with salt, pepper, and a spoonful of Cajun seasoning.

3. Pour in the chicken broth and heavy cream. Stir to combine, scraping up any bits from the bottom. Let it simmer on low for 5 to 7 minutes.

4. While the sauce is simmering, boil rotini in salted water until al dente. Reserve 1/4 cup of pasta water and drain the rest.

5. Stir cooked pasta into the sauce, add Parmesan cheese, and mix well. Use a splash of reserved pasta water if needed to adjust consistency.

6. Taste and adjust seasoning if desired. Let everything simmer together for 2 more minutes.

7. Serve hot, optionally topped with extra Parmesan and a sprinkle of fresh herbs.